A new highly-effective class of low molecular weight brominated aromatic polymer compositions has recently been discovered in our laboratories. These compositions have the formula:C6H(5-x)BrxCH2CH2(C6H(5-x)BrxCHCH2-)nCH2C6H(5-x)Brx wherein n is an average number in the range of about 2.9 to about 3.9, wherein each x is the same or different and is a whole number in the range of 3 to 5, the average number of all of the x's in the composition being in the range of about 3.50 to about 3.80 and the weight percent of bromine as determined by X-Ray Fluorescence Spectroscopy (XRF) in the polymer being in the range of about 73.4 to about 74.5 wt %. A detailed description of these new brominated aromatic polymer compositions and their preparation and uses is presented in commonly-owned Provisional U.S. Patent Application No. 61/119,289, filed Dec. 2, 2008, all disclosure of which is incorporated herein by reference.
The process technology described in the foregoing Provisional patent application yields products having a combination of desirable properties. Nevertheless, it would be of advantage if still further improvements in the process technology could be found whereby the process would be even more efficient in terms of utilization of articles of commerce and reduced product quality sensitivity to recycle streams, in particular recycled bromination solvents. Additionally, it would be of advantage if these process improvements could be achieved without sacrifice of key flame retardant characteristics such as initial solution color, Hunter Color Yellowness Index, thermal color stability, and minimal thermal HBr content. Indeed, it would be of considerable advantage if one or more of these properties could be enhanced while achieving the foregoing further improvements in process technology.
This invention is deemed to have achieved most, if not all, of these objectives in a highly efficient and effective manner.